新型弯起器研制及其对钢铰线力学性能影响Ⅰ:强度与延性  

Development of New Bending Component and Its Influence on Mechanical Property of Steel Strand Ⅰ:Strength & Ductility

作　　者：黄文雄[1,2] 谭利英 

机构地区：[1]长江大学城市建设学院,湖北荆州434023 [2]长江大学设计研究院,湖北荆州434023 [3]荆州市城市规划设计研究院,湖北荆州434000

出　　处：《公路交通科技》2013年第2期49-54,共6页Journal of Highway and Transportation Research and Development

基　　金：住房和城乡建设部科学技术计划项目(2011-K2-23);湖北省教育厅科学技术研究项目(Q20111314)

摘　　要：为了消除"折点"效应,改善折线配筋先张梁弯起器部位钢绞线的应力状态,选用优选半径R=600 mm为导向半径,采用导向构件与支撑心轴的组合构件代替原导向辊,设计并研制了构造简洁、拼装灵活的新型折线配筋先张梁弯起器。为了研究新型弯起器对钢绞线力学性能的改善作用,采用试验方法,研究了采用不同导向半径R及不同弯折角度θ时,弯起器对钢绞线极限强度、延性性能的影响规律,并深入分析了试验现象与影响规律的产生机理。试验结果表明:随着R的增大钢绞线强度与延性性能的折减效应呈对数曲线趋势减小,当R≥100 mm时,R与θ的变化对钢绞线力学性能的影响较小;说明弯起器导向半径R在满足结构尺寸与构造要求前提下应尽量取大值,受限时也不宜小于100 mm,从而验证了新型弯起器的科学性。In order to eliminate the harmful effects of inflection point and improve the stress state at the bending component of steel strand of polyline pretensioned beam （PPSCB） , a new bending component of PPSCB, whose structure is simple and easy to assemble, is developed. The new bending component is based on the roller bending component, the roller is replaced by a combined member constituted by a guiding device and two mandrels, and the optimized radius R = 600 ram. The experiment is designed to study the influence of the new bending component on the mechanical property of steel strands. The regularity and the mechanism of the ultimate strength and ductility of steel strands affected by the radius R and the bending angle 0 is analyzed. The result shows that （ 1 ） with the increase of R, the reduction effect of the ultimate strength and ductility of steel strands decrease which conforms to the rule of logarithmic function; （2） when R 〉I 100 ram, the mechanical property of steel strand is less affected by the variation of R and 0. It indicates that the radius of the bending component should be as large as possible when the dimensions of bend component meet the structure and configuration requirement, and it should not less than 100 mm when the size is limited. Thus the scientific nature of the new bending component is confirmed.

关 键 词：桥梁工程 折线配筋先张梁 弯起器 试验 力学性能 钢绞线 极限强度 延性 

分 类 号：U448.35[建筑科学—桥梁与隧道工程] TU757.13[交通运输工程—道路与铁道工程]